On July 5, 2015, bestselling author and sustainability researcher Thomas Homer-Dixon was standing on a cliff on southern Vancouver Island overlooking the Juan de Fuca Strait. He could see the Olympic Mountains in Washington state. But then this magnificent view was suddenly marred by a dense cloud of brown wildfire smoke overhead, appearing like a “gigantic scythe”.
Homer-Dixon described this scene in this way in his 2020 book, Commanding Hope: The Power We Have to Renew a World in Peril: “Soon, the cloud transformed the sun into a feeble orange disc, dusk fell in midafternoon, and the vivid colors of the sea and forest around me faded away.”
Six years ago, an event like this was virtually unprecedented in Greater Victoria. Homer-Dixon was in a position to know this because his father, Doug, was born in Victoria in 1926 and had been the chief forester of the Greater Victoria Water District from 1953 to 1991.
“My dad was very ill at that point,” Homer-Dixon recalled in an interview with the Straight last year. “He was a few weeks from passing away but he was completely lucid. He said, ‘I haven’t seen anything like this.’ ”
Since then, that is no longer that unusual in southwestern British Columbia. In the summer of 2017, satellite images from NASA showed that much of the South Coast was shrouded in wildfire smoke emanating from the B.C. Interior.
A similar thing happened in 2018, when Metro Vancouver was under an air-quality advisory for 22 consecutive days due to dense concentrations of wildfire smoke. Then, in 2020, Metro Vancouver’s air quality was rated as worse than that of New Delhi as a result of wildfire smoke moving north from the U.S. Pacific Northwest.
This summer is shaping up as another horrific wildfire season in B.C., thanks in to record temperatures.
The scientific director in environmental health services at the B.C. Centre for Disease Control (BCCDC), Sarah Henderson, conceded in an interview with the Straight that she can’t predict what the weather over the next two months.
“We haven’t yet seen those conditions that we’ve seen in other summers where the weather and the smoke interact to hold the smoke really close to the surface of the Earth [where] there’s heavy smoke everywhere for days and weeks,” she said. “That’s what we saw in 2017 and 2018.”
But Henderson added that B.C. could experience similar conditions again. That’s why she advises people to have a plan for how they’re going to behave when it gets smoky.
“That means understanding your own susceptibility and the susceptibility of your family and the people in your community,” she said. “It means talking to your physician if you have a chronic condition, such as asthma or COPD [chronic obstructive pulmonary disease] and making sure that you have an action plan in place.”
Chronic disease suffers face greater risks
She also said that there’s “early evidence” of slightly reduced birth weights for infants who were in utero during big smoke events.
Henderson explained that infants, and particularly newborns, have sensitive lungs. And she said that a study of monkeys in California concluded that for these primates, early exposure can have “lifelong health implications”.
“What we don’t know very much about at this point is preterm births and other adverse birth outcomes like that,” Henderson noted.
Michael Brauer, a UBC professor of occupational and environmental health, coauthored a paper last year examining the links between ambulance dispatches in B.C. and exposure to fine particulate matter less than 2.5 microns in diameter during wildfire seasons. Brauer and the other researchers reported that just an hour of exposure was associated with greater hospitalizations for some respiratory and cardiovascular conditions.
Brauer told the Straight by phone that this included “a worsening of asthma or a worsening of COPD”.
In addition, there were more hospitalizations for those with diabetic conditions 24 hours after exposure to increased particulate matter in wildfire season.
When it comes to those who have partially recovered from COVID-19, Brauer said there’s no direct evidence that such people are more sensitive to the effects of wildfire smoke. “But I would expect they are, especially people who are still suffering symptoms like heavy breathing,” Brauer said.
Then there's the issue of heat waves coinciding with major wildfire smoke events.
According to Brauer, some of the best research into this took place in Moscow, where there were soaring deaths in the summer of 2010, according to the government.
"It's kind of a one plus one equals more than two situation if we have heat and smoke at the same time," Brauer said.
When this occurs, people might want to think about going to clean-air shelters—with air conditioning and air purifiers—if they're living in homes without air conditioning and don't want to open the windows.
Researchers track toxicity of smoke
A 2020 study published in Science of the Total Environment estimated that there were 54 to 240 annual premature mortalities “attributable to short-term exposure” from wildfire smoke in Canada and another 570 to 2,500 annually “attributable to long-term exposure”. Henderson was a coauthor of the study, which looked at the years 2013 to 2015 and 2017 and 2018.
"The economic valuation of the population health impacts was estimated per year at $410M-$1.8B for acute health impacts and $4.3B-$19B for chronic health impacts for the study period," it stated.
Another paper published in the journal Nature in March highlighted how bad wildfire smoke can be to the human body. It cited recent studies suggesting that particulate matter of 2.5 microns or less in diameter from wildfires may be more toxic than equal doses of ambient particulate matter of the same size. In some cases, particulate matter from wildfires was up to 10 times more harmful.
According to the paper in Nature, one study showed that certain toxic substances, such as polycyclic aromatic hydrocarbons, were present in far higher concentrations in wildfire smoke than in ambient particulate matter. Another study found that wildfire smoke contributed to “higher cell degeneration and potential programmed cell death”.
As a result, it “may be inaccurate” to assume that all particles of a given size have the same toxicity, the paper stated. This has implications for organizations such as Metro Vancouver, which regulate air quality.
Meanwhile, ultrafine particles smaller than 0.1 micron in diameter can actually pass through lung tissue and enter the bloodstream, according to the American Lung Association. If these particles are highly toxic, that creates more health concerns.
At the BCCDC, Henderson has been following the scientific literature on wildfire smoke. She pointed out that researchers in labs are looking at the toxicological profile of smoke from various trees—including pines, eucalyptuses, and oaks—as well as how the smoke differs from higher- versus lower-temperature fires.
She said she’s glad that this research is being done, characterizing it as “academically interesting”. But she said that when you zoom out to the level of it being a smoky day in this region and 2.5 million people are affected, it doesn’t really matter because such findings can’t be applied to the situation.
“From a practical perspective, there’s nothing I can really take from that literature to change the way I’m going to communicate as a public-health professional about wildfire smoke,” Henderson said. “I think the same is likely true with what happens to particles once they get into your body.”
Homemade air purifiers can help
That’s not to say that nothing can be done—far from it. The first thing people should think about is keeping windows closed to prevent wildfire smoke from entering the home.
In addition, parents concerned about their babies and children can take steps to purify the air in one or more rooms in the home. If people can’t find any air purifiers in stores during a major smoke event, they can create a homemade device using a 20-inch X 20-inch box fan and attaching a furnace filter on the back of it.
“We’ve put instructions on how to do that on the BCCDC website,” Henderson said.
She’s actually tested these devices with one of her research colleagues who has an air-pollution exposure chamber used to test human subjects. “We found out that they worked quite well.”
However, Henderson strongly recommended keeping an eye on these homemade air purifiers because there could be a fire risk.
“It puts an extra burden on the motor because it has to pull air through that filter,” Henderson said. “So you’re using an electrical device for something it’s not designed to do.”
It can get complicated if a wildfire-smoke event coincides with extreme heat. In this instance, Henderson said that the health risk from overheating is usually greater than the risk from wildfire smoke.
So if it makes sense to open the windows, then that should be done.
Masks offer some relief
Then there’s the issue of masks—something the public is much more used to wearing nowadays. According to Henderson, the most effective for wildfire-smoke protection are particle respirators—i.e., masks with a letter and a number, like N95 or KN95.
“If they are well fitted to your face—meaning the air is going through the material of the mask and not around it—they can be quite effective for reducing the fine-particle exposure, but the gases are still going to get through there,” she said.
Brauer pointed out that respirator masks can provide protection up to 90 percent if worn properly. That compares to about 20 or 30 percent protection with surgical or cloth face coverings.
Because respirators can be uncomfortable after a while, Brauer said that it might be wise to wear them when smoke concentrations are at their greatest. According to him, that can occur in the morning and the evening.
For his part, Thomas Homer-Dixon sees great symbolism in wearing masks to respond to wildfire smoke. And he wonders if it might help turn the tide toward taking bolder action to address the climate crisis.
“Something about inhaling toxins—pathogens—into our bodies terrifies people,” Homer-Dixon told the Straight last year.
Moreover, he said, masks are associated with poison gas, which is something humanity has decided is completely unacceptable.
“We know a million ways to kill people in warfare that are just as bad or worse than poison gas,” Homer-Dixon acknowledged, “yet poison gas is something we’ve decided is absolutely wrong.”